Embodiments of the present invention generally relate to surgical laser systems, laser pulse trains produced by such systems, and methods of performing laser lithotripsy using the systems and laser pulse trains.
Medical lasers have been used in various practice areas, such as, for example, urology, neurology, otorhinolaryngology, general anesthetic ophthalmology, dentistry, gastroenterology, cardiology, gynecology, and thoracic and orthopedic procedures. Generally, these procedures require precisely controlled delivery of laser energy as part of the treatment protocol.
The treatment of kidney or bladder calculi or stones, Lithotripsy, is currently achieved through either ESWL (extra-corporal sound wave lithotripsy), surgery, or use of a laser (laser lithotripsy). In the laser application, a holmium doped yttrium aluminium garnet (Ho:YAG) laser rod, or a thulium doped yttrium aluminium garnet (Tm:YAG) laser rod are used to produce laser energy having a wavelength of around 2000-2100 nm to break up stones of all types. The laser energy is typically in the form of a train of laser pulses, each having long pulse widths, such as approximately a few hundred microseconds. It is believed that a thermo-mechanical mechanism of action is in play for breaking up the stones, namely the laser energy superheats water in the vicinity of the stone, and creates a vaporization bubble. The vaporization bubble then expands and destabilizes the stone, causing it to fragment.
There is a continuous demand for improvements to laser lithotripsy procedures including improved fragmentation of the stones, for example.